Ignition distributors

ABSTRACT

A method of assembling an ignition distributor of the kind which includes a base plate which is secured to the casing of the distributor and a timing plate which is mounted for angular movement on the base plate includes the steps of engaging a first annular plate with an annular base plate so that three projections provided on the first plate extend through corresponding apertures in the base plate. The three projections of the first plate are so disposed that any one of the projections is on the opposite side of a diameter of the first plate from the remaining projections. The portions of the projections which extend from the base plate are then subject to a levelling operation so that the free ends of the projections lie in a common plane parallel to, but above the plane of the base plate. A third annular plate is then engaged with the free ends of the projections where they extend from the base plate, and resilient means is utilized to couple the first plate and the third plate to define an assembly. The resilient means urges the third plate towards the first plate, and the first or third plate includes a cylindrical spigot which extends through a hole in the base plate, so that the assembly of the first and third plates is movable angularly relative to the base plate. Either the first plate, or the third plate constitutes the timing plate of the distributor in use, and carries the contact breaker assembly of the distributor.

United States Patent Cooksey 1 Sept. 5, 1972 [54] IGNITION DISTRIBUTORS [72] Inventor: William Harold Cooksey, 5, Penryn Close, Park Hall, Walsall, England [22] Filed: Aug. 12, 1970 [21] Appl. No.: 63,247

[30] Foreign Application Priority Data Aug. 12, 1969 Great Britain ..40,l88/69 [52] US. Cl. ..29/598, 200/ 19 R [5l] Int. Cl. ..H02k 15/02 [58] Field of Search ..29/437, 438, 598; 200/l9 R, 200/19 A, 19 B, l9 L, 19 E, l9 D, 19 DC, 19

M, 19 TS, l9 WG; 310/42 [56] References Cited UNITED STATES PATENTS 1,337,322 4/1920 Norman ..200/19 R 3,412,222 11/1968 Soeters ..200/19 A Primary Examiner-Robert L. Spicer, Jr. Attorney-Holman & Stern [57] ABSTRACT A method of assembling an ignition distributor of the kind which includes a base plate which is secured to the casing of the distributor and a timing plate which is mounted for angular movement on the base plate includes the steps of engaging a first annular plate with an annular base plate so that three projections provided on the first plate extend through corresponding apertures in the base plate. The three projections of the first plate are so disposed that any one of the projections is on the opposite side of a diameter of the first plate from the remaining projections. The portions of the projections which extend from the base plate are then subject to a levelling operation so that the free ends of the projections lie in a common plane parallel to, but above the plane of the base plate. A third annular plate is then engaged with the free ends of the projections where they extend from the base plate, and resilient means is utilized to couple the first plate and the third plate to define an assembly. The resilient means urges the third plate towards the first plate, and the first or third plate includes a cylindrical spigot which extends through a hole in the base plate, so that the assembly of the first and third plates is movable angularly relative to the base plate. Either the first plate, or the third plate constitutes the timing plate of the distributor in use, and carries the contact breaker assembly of the distributor.

3 Claims, 3 Drawing Figures PAIENTEDsEPSmIZ 3.688.391

' SHEETlUF 2 rNVENTOR Ma d 6001947 ATTQRNEYS PATENTEDSEP 1m 3.688.391

SHEET 2 BF 2 QINVENTOR ATTORNEX IGNITION DISTRIBUTORS This invention relates to a method of assembling ignition distributors of the kind including a base plate which is secured to the casing of the distributor and a timing plate mounted for angular movement on the base plate, the timing plate, carrying the contact breaker assembly of the distributor.

A method according to the invention includes the steps of engaging a first annular plate with an annular base plate so that three projections on the first plate extend through corresponding apertures in the base plate, the three projections of said first plate being so disposed that any one of the projections is on the opposite side of a diameter of the first plate from the remaining projections, performing a levelling operation on the free ends of the projections extending from the base plate so that the free ends of the projections lie in a common plane parallel to and spaced from the face of the base plate remote from the first plate, engaging a third annular plate with the free ends of the projections, and coupling the first and third plates by resilient means which urges the first and third plates towards one another, the assembly defined by the first and third plates and the base plate having mating surfaces which mount said assembly for angular movement relative to the base plate and one of said first and third plates constituting the timing plate of the distributor in use.

In the accompanying drawings,

FIGS. 1 and 2 illustrate two stages of a method, according to one example of the invention, of assembling an ignition distributor, and

FIG. 3 is a diagrammatic representation of the distributor assembled.

Referring to the drawings, there is provided an annular base plate 11 including a pair of integral, diametrically opposite lugs 12. The plate 11 is formed with three, equi-angularly spaced arcuate slots 13 which lie on the circumference of an imaginary circle concentric with the central aperture 14 in the plate 11. There is further provided an annular timing plate 15 the wall of the central hole of which is extended to define an axially extending spigot 16 The plate 15 is engaged with the plate 11 with the spigot 16 extending through the hole 14 of the plate 11, and three equi-angular spaced projections 17 on the plate 15 extending through the slots 13 of the plate 11. The plate 15 is engaged with the flat top surface of a fixed anvil 18, and a movable stepped planishing tool 19 is engaged with the tops of the projections 17, projecting from the plate 11. The plate 11 is used as a stop for the planishing tool 19, and the tops of the projections 17 are levelled by the tool 19 so as to lie in a common plane parallel to and spaced above the plate 11. The tool 19 is then removed, and a further annular plate 21 is placed in contact with the tops of the projections 17, The spigot 16' extends through the central hole 22 in the plate 21 the spigot 16 being a close fit in the hole 22.

An annular spring washer 23 having three equi-angularly spaced resilient legs 24 is then threaded over the spigot 16 so that the legs 24 engage the plate 21. The legs 24 are bent out of the plane of the remainder of the washer 23, and so the remainder of the washer 23 is spaced from the plate 21 when the legs 24 engage the plate 21. The free end of the spigot 16 is formed with a circumferential groove 25, and the dimensions of the parts are such that when the washer 23 is unstressed the Circular portion of the washer 23 is positioned on the side of the groove 25 remote from the plate 15. The circular portion of the washer 23 is then urged towards the plate 15 thereby stressing the legs 24, and moving the circular portion of the washer 23 to the side of the groove 23 adjacent the plate 15. A circlip 26 is then engaged in the groove 25 to retain the washer 23 in its stressed condition, the washer 23 acting against the plate 21 to urge the plate 15 towards the plate 21. However, since the projections 17 were levelled so that their free ends lie in a plane spaced above the plane of the plate 11, then the plates 21, 15 although urged firmly into engagement with one another are not urged by the spring washer 23 into engagement with the plate 11, and a clearance equal to the difference between the thickness of the plate 11, and the heights of the projections 17 is left between the assembly of plates 15, 21, and the plate 11.

The diameter of the hole 14 in the plate 11 is substantially equal to the external diameter of the spigot 16, and so the spigot 16 serves to mount the assembly of plates 15, 21 on the plate 11 for relative movement to the plate 11 about the axis of the spigot 16. The degree of angular movement of the assembly of plates 15, 21 relative to the plate 11 is limited by engagement of the projections 17 with the ends of their respective slots 13. It will be appreciated that tolerances involved in the manufacture of the plate 11 will not affect the clearance between the plate 11 and the assembly 15, 21 since the plate 1 1 is used as the stop for the tool 19 during planishing of the projections 17.

In use, the assembly of the plates 11, 15, 21 is inserted into the casing 31 of an ignition distributor with the plate 15 uppermost, and the cam shaft 32 of the distributor extending co-axially through the spigot 16. The assembly is secured to the casing 31 by screws which pass through holes in the lugs 12 of the plate 11, and the contact breaker assembly of the distributor is mounted on the upper surface of the plate 15. A vacuum unit is secured to the casing of the distributor, and is operatively connected to the plate 15 by means of a connecting rod, so that during operation of the vacuum unit the plate 15 carrying the contact breaker assembly, together with the plate 21 is moved angularly relative to the plate 11 about the axis of the cam shaft 32 of the distributor to vary the ignition timing of the distributor. I

It will be appreciated that sincethe contact breaker assembly moves on an arc of a circle having its center on the axis of the cam shaft, then movement of the plate 15 to vary the ignition timing of the distributor will not alter the operating gap of the contacts of the contact breaker assembly.

In a modification the projections 17 are formed on the plate 21, and the plate 21 and the plate 11 are interengaged prior to the planishing operation to level the top of the projections 17. The plate 21 will of course also carry the spigot 16, so that the plate 21 and the plate 11 are accurately located relative to one another during the planishing operation, and the legs 24 of the spring 23 will of course engage the plate 17, the spring 23 being so shaped that it does not obstruct the contact breaker assembly.

It will be appreciated, that since the clearance between the plates 15, 21 and the plate 11 is determined by the projections 17, then the plate 15, 21 can be urged towards one another with sufficient force to minimize vibration of the plates 15, 21 relative to one another in use, without substantially altering the clearance between the plates 15, 21 and the plate 11.

In practice the plates 15 and 21 will be provided with nylon bearing pads which engage the plate 11, the pads minimizing the friction between the plates 15, 21 and the plate 11. Moreover the casing 31 is closed in use by an insulating cap 33.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:-

1. A method of assembling an ignition distributor of 15 of the projections extending from the base plate so that the free ends of the projections lie in a common plane parallel to and spaced from the face of the base plate remote from the first plate, engaging a third annular plate with the free ends of the projections, and coupling the first and third plates by resilient means which urges the first and third plates towards one another, the assembly defined by the first and third plates and the base plate having mating surfaces which mount said assembly for angular movement relative to the base plate and one of said first and third plates constituting the timing plate of the distributor in use.

2. A method as claimed in claim 1 wherein said first plate constitutes the timing plate of the distributor in use.

3. A method as claimed in claim 1 wherein the first plate includes a cylindrical spigot which extends through a circular hole in the base plate and which is engaged with the third plate, said spigot serving to mount the first and third plates for angular movement on the base plate.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Pat nt No. 3,688,391 Dated Sept; 5, 1972 Inventor(s) William Harold Cooksey It is certified that error appearsin the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

[73] Assignee: Joseph Lucas (Industries) Limited, Birmingham, England Signed and sealed this 9th of January 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. I ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents USCOMM-DC 60376-P69 Q US. GOVERNMENT PRINTING OFFICE: 959 O'366-334 FORM PO-IOSO (10-69) UNITED STATES PATENT OFFICE CETEFECATE 0E QOUHUN Patent No- 3,688,391 Dated Sept. 5, 1972 Invent (s) William Harold Cooksey It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

{73] As signee: Joseph Lucas (Industries) Limited, Birmingham, England Signed and sealed this 9th of Januar 1973s (SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Commissioner of Patents Attesting Officer USCOMM-DC 6O376-P69 u.s GOVERNMENT PRINTING OFFICE 1969 oaes-334 ORM PO-105O (10-69) 

1. A method of assembling an ignition distributor of the kind specified including the steps of engaging a first annular plate with an annular base plate so that three projections on the first plate extend through corresponding apertures in the base plate, the three projections of said first plate being so disposed that any one of the projections is on the opposite side of a diameter of the first plate from the remaining projections, performing a levelling operation on the free ends of the projections extending from the base plate so that the free ends of the projections lie in a common plane parallel to and spaced from the face of the base plate remote from the first plate, engaging a third annular plate with the free ends of the projections, and coupling the first and third plates by resilient means which urges the first and third plates towards one another, the assembly defined by the first and third plates and the base plate having mating surfaces which mount said assembly for angular movement relative to the base plate and one of said first and third plates constituting the timing plate of the distributor in use.
 2. A method as claimed in claim 1 wherein said first plate constitutes the timing plate of the distributor in use.
 3. A method as claimed in claim 1 wherein the first plate includes a cylindrical spigot which extends through a circular hole in the base plate and which is engaged with the third plate, said spigot serving to mount the first and third plates for angular movement on the base plate. 